Electric switch



F. D. PATTI ELECTRIC SWITCH July 31, 1962 Filed May 21, 1959 1IIIIIIIIIIII/A I 4 VII/I mu t United States Patent "ice 3,047,699ELECTRIC SWITCH Fred D. Patti, 1371 Division St., Morris, Ill. Filed May21, 1959, Ser. No. 814,817 Claims. (Cl. 200-159) This invention relatesto a switching mechanism for controlling an electric circuit, and moreparticularly a switching mechanism of the type having an actuatingmember of constant stroke between operated and return positions ofadjustment and movable from one to the other of said positions inresponse to displacement of said actuating member from a selected normalposition corresponding to a first condition of a surface engaged by saidactuating member to a selected abnormal position corresponding to asecond condition of a surface engaged by said actuating member untilsaid surface engaged by said actuating member is restored to said firstcondition. Tip-over switches for opening the electric circuit to anelectrically operated room heating appliance represent a switchmechanism of the type with which this invention, in one example thereof,has specific application.

It is an object of this invention to provide a switch of the characterindicated embodying novel features of construction and design which notonly offers accuracy of operation but an assembly and arrangement ofparts Which lends itself to simple and relatively inexpensivemanufacture as well as application.

Additional features and advantages of this invention will becomeapparent as the following description proceeds and the features ofnovelty which characterize this invention will be set forth in theclaims appended to and forming a part of this specification.

For a more complete understanding of this invention reference is had tothe accompanying drawings in which:

FIG. 1 is a side elevation, partly in section, of an electricallyoperated room heating unit showing the switch mechanism embodying thefeatures of this invention, with the actuating member in operatingposition.

FIG. 2 is an enlarged view taken along line 22 of FIG. 1 in a directioninwardly of the appliance to which it is secured.

FIG. 3 is an enlarged sectional view taken along line 3-3 in thedirection of the arrows appearing in FIG. 2.

Reference being had more particularly to the drawings, numeraldesignates a bracket or base plate to which the end portion of a firstcontact arm 11 and an end portion of a second contact arm 12 arefastened in stacked arrangement about a hollow rivet 13 passing throughan opening in the bracket 10 for permanent attachment to the latter,with the arm 12 and the base 10 in straddling relation to arm 11. Rivet13 also supports a terminal lug 14 in electrical contact with arm 11 aswell as a terminal lug 15 in electrical contact with arm 12. Contact arm11 and its terminal lug 14 are supported on the rivet 13 in spacedopposed relation to the bracket 10 by means of an insulating spacer 16.The contact arm 12 and its terminal lug 15 are supported in spacedopposed relation to the contact arm 11 and its terminal lug 14 by aninsulating spacer 17. A third insulating spacer 17 is supported on therivet 13 between the contact arm 12 and its terminal lug 15 and the head18 at the end of the rivet 13 remote from the bracket 10.

A contact 19 is carried at the outer end of the contact arm 11 facingthe contact arm 12 and a similar contact 20 is mounted on the outer endof the contact arm 12 facing the contact 19 on contact arm 11. Thecontact arm 11 is resiliently biased in a direction away from thecontact arm 12 causing the contact 19 on the arm 11 to normally occupy aposition at a distance away from the contact 20 on the arm 12.

Patented July 31, 1962 The bracket 10 is also provided with a sleeve 21,said sleeve having a reduced end portion 22 passing through an opening23 in the bracket 10 for arrangement along an axis in spaced parallelrelation to the rivet 13 and substantially in alignment with thecontacts 19 and 20 on the arms 11 and 12, respectively. The sleeve hasopposed flats 24 for acceptance in a non-circular opening in the wall 26of an appliance such, for example, as an electric space heater, wherebythe sleeve is trapped against rotation relative to the opening in thewall 26.

Threads 27 on the exterior of the sleeve 21 cooperate with nuts 28 and29 engaging said threads to establish a rigid connection between thesleeve 21 and the wall 26 of the appliance in which the sleeve 21 ismounted.

A rod 30 is slidably supported in the sleeve 21 for v movement inwardlyof the area occupied by the contact arm 11, corresponding to anoperating position as shown in FIG. 1 and for movement outwardly of saidarea corresponding to a return position as shown in FIG. 3. Aninsulating tip 31 suitably mounted on and forming an inward extension ofthe rod 30 is engaged by the surface of the contact arm 11 opposite theinner end of said tip 31. The stress of the contact arm 11 whichnormally urges the contact 11 in a direction away from the contact arm12 is effective to exert pressure against the tip 31 in a correspondingdirection with the result that the rod 31 is thereby resilientlymaintained in a return position as shown in FIG. 3. A stop ring 32 fixedto the portion of the rod 30 inwardly of the wall 26 has engagement withthe inner limits of the sleeve 21 to limit the travel of the rod 30 inan outward direction thereby establishing the return position of saidrod 30. The distance which the rod 30 travels to reach an operatingposition corresponds to the distance between the contacts 19 and 20,and, as shown in FIG. 1, the outer end of the rod 30 is situated incoplanar relation to the support engaging surfaces of feet 33 secured toand projecting downwardly from the wall 26 of the heating unit when therod 30 is in such operating position. Thus, while the feet 33 havedownward engagement with a supporting surface opposite thereto (saidsurface being rep-resented by a straight line along the bottom ofFIG. 1) and the heating unit is thereby maintained in erect position,the cont-act arm 11 yields to the inward pressure applied thereto by thetip 31 of the rod 30 via gravitational force exerted by the heating unitin the direction of said supporting surface opposite the outer end ofthe rod 30, to move said contact arm 11 toward the contact arm 12 and toaccordingly bring contact 19 into circuit closing engagement withcontact 20. When the heating unit is displaced from such erect position,as, for example, tipped over, and the resistance to outward movement ofthe rod 30 is no longer supplied by the supporting surface, the inherentstress of the contact arm 11 urging its movement to a return positionallows the contact 19 to move out of engagement from the contact '20,thereby opening the circuit.

While the distance travelled by the rod 39 between its operating andreturn positions remains constant in relation to the bracket 10, thelocation of the latter relative to the wall 26 may be varied along thelength of the sleeve 21 by adjusting the nuts 28 and 2-9 to a selectedposition corresponding to the desired position of the bracket 10relative to said wall 26. Thus the distance from said wall 26 to theouter end of the rod 30 may be conveniently varied to suit specificrequirements of a wide range of different appliance designs as well as avariation in type of installation with which the switch of thisinvention might be associated.

It will be understood whether either of the contact arms 11 and 12 isresiliently biased to occupy one of two positions relative to the othercontact arm, movement of the rod 30 toward or away from the areaoccupied by said contact arm in its normally biased position may beutilized to establish engagement or disengagement of the contactscarried by said arms. Such movement of the rod 30 is likewise availableas actuating means with which the resiliently biased contact arm hasengagement whether the rod 30 enters the area occupied by saidresiliently biased contact arm from a direction in which either of saidarms is nearest to the line of approach of said rod 30 as it enters saidarea. Accordingly a wide range of variations in the arrangement of thecontact arms 11 and 12 to each other as well as the direction ofmovement of the rod in relation to the area occupied by said contactarms is available in a switch assembly embodying the features of thisinvention.

Since the switch assembly of this invention provides a completepre-assembled unit embodying mounting means to fit a given opening inthe framework of a product requiring use of a switch controlled by anopera-ting member, the manufacturer of such a product is able to avoidthe need to maintain an inventory of parts as heretofore required inconnection with switches of the character indicated. Productionoperations are also confined to the simple step of fitting the singlemounting part of the switch in the opening provided therefor.Furthermore, the mounting means with which the present switch isequipped allows for convenient adjustment to correctly accommodatevarying conditions of clearance conditions in the path of the actuatingmember thereby increasing the adaptability of this switch assembly fromone form of installation to another.

While the foregoing description is now believed to be a preferredembodiment of the invention, it is to be understood that changes andmodifications may be made therein as indicated without departing fromthe spirit of this invention, and it is intended that all such changesand modifications be included within the scope of the appended claims.

What is claimed is:

1. A switch including a base, first and second contact arms, stack meansrigidly joining said base and said arms in superposed relation with oneof said arms and said base in straddling relation to the other of saidarms, said stack means extending along an axis perpendicular to theplane of said base, said first contact arm being movable relative to thesecond contact arm between operating and return positions and biased tonormally occupy one of said positions, a contact on said first contactarm engageable with a contact on said second contact arm when said firstarm is in operating position, and means for securing said switch to asup porting panel, said means including a sleeve fixed to said base todefine a tubular guidelway leading to the area occupied by said firstarm along an axis parallel to the axis of said stack means, said sleevebeing externally threaded, a pair of nuts having threaded connectionwith said threads on said sleeve which nuts provide opposed surfacesbetween which said supporting panel may be engaged along edge portionsof an opening in said supporting panel at selected positions along thelength of said sleeve, and an actuating member with which the firstcon-tact arm is engageable at a free end thereof to move said first armrelative to said second arm toward a position opposite to the normallybiased position of said first arm, said actuating member comprising arod having guided movement in said sleeve toward and away from the areaoccupied by said first arm.

2. A switch according to claim 1 wherein a stop on said rod hasengageable relation with an end portion of said sleeve to limit movementof the rod in a direction away from said first contact arm.

3. A switch according to claim 1 wherein said first contact arm isbiased toward said return position.

4. A switch according to claim 1 wherein said first contact arm isbiased toward said return position, and said first contact arm isoperative to urge said rod in a direction away from said first contactarm.

5. A switch according to claim 1 wherein a stop on said rod hasengagement with an end portion of said sleeve to limit movement of therod in a direction away from said first contact arm, and said rod isurged toward said limit of movement under stress applied by said firstcontact arm.

References Cited in the file of this patent UNITED STATES PATENTS2,521,015 McLaren et al. Sept. 5, 1950 2,547,765 Lund Apr. 3, 19512,583,754 Theisen Jan. 29, 1952 2,707,745 Farr et al. May 3, 19552,897,321 Patti July 28, 1959

